// Copyright 2025 International Digital Economy Academy
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

///|
fn k_expo2f(x : Float) -> Float {
  let k = 235
  let k_ln2 = (0x4322e3bc).reinterpret_as_float()
  // note that k is odd and scale*scale overflows */
  let scale = ((0x7f + k / 2) << 23).reinterpret_as_float()
  // exp(x - k ln2) * 2**(k-1) */
  (x - k_ln2).exp() * scale * scale
}
